This is the R614FF 2.4 GHz FASST Receiver
for use with the Futaba 2.4GHz 4PK and 4PKS Surface Radio System.

FEATURES

Futaba's FASST (Futaba Advanced Spread Spectrum Technology) shifts
very quickly virtually eliminating signal conficts and
interruptions unlike other 2.4GHz systems that only stay on one
or two frequencies.
Small and lightweight, for surface use only
One year limited warranty through Hobby Services beginning at date of
purchase